End mill sharpening device



July 11; 1967 H. s. slzmsm 3,330,073 I END MILL SHARPENING DEVICE Filed Nov. 16, 1964 mvmrroll HENRY S. S/EMsE/V A TTORNEY United States Patent 3,330,073 END MILL SHARPENING DEVICE Henry S. Siemsen, 11910 W. Jefferson Blvd., Culver City, Calif. 90230 Filed Nov. 16, 1964, Ser. No. 411,268 7 Claims. (Cl. 51-95) ABSTRACT OF THE DISCLOSURE An end mill sharpening device which maintains the concentricity of the end mill during the sharpening operation. A first set of three rollers is mounted on one end of three spindles. The end mill is mounted between and held by such rollers.

A second set of three rollers is mounted on the opposite ends of the spindles. A sizing and guiding member has its shank mounted between and held by the second set of rollers. The sizing and guiding member preferably has a shank'corresponding in sizeto that of the end mill being sharpened, so that the end mill holding rollers are thereby adjusted to the size of the end mill. The sizing and guiding member has a protruding gripping portion which is manually rotated to control the rotation of the end mill during the sharpening operation.

This invention relates to a device for sharpening end mills. While my device is particularly useful for re-sharpening end mills which have been used and become worn, it is also capable of being used in the original sharpening of end mills when they are first manufactured.

In sharpening an end mill, it is extremely important that the concentricity of the shank be maintained, so that the end mill is as concentric as possible after the sharpening operation. It is the primary object of my invention to provide a device in which this concentricity is assured and maintained to a substantially greater de gree than with devices of the type which are now in use.

At the present time, the end mills are customarily held during the sharpening operation by means of a draw bar which has a number of variables, each of which tends to cause the end millto become out'of concentricity, and all of which can be cumulative in order to cause a greater lack of concentricity.

It is an object of my invention to provide an end mill sharpening device which includes holding means for gripping the shank of the end mill, such holding means being so formed that there are no variables and each end mill is concentric after being sharpened.

A further object of my invention is to provide such a holding means in which the parts will not become worn through use or in which any wear will not adversely afiect the concentricity of the sharpened end mill.

Another object of my invention is to provide such a holding means which is adjustable to accommodate the wide range of diameters of end mills, with each end mill being held and sharpened concentrically.

It is a further object of my invention to provide an end mill sharpening device which is substantially simpler and more certain in use than the devices now employed. As a result, a new worker can be trained to use my'device properly within a few days, as opposed to several months of training required to learn and properly use devices of the type now employed.

Still another object of my invention is to provide a device of the type described which can not only be used for sharpening various sizes of end mills, but which in one embodiment of the invention can also be used for sharpening both right and left hand end mills.

A further object of my invention is to provide a device of the type described which is essentially simple and economical to manufacture and which is more reliable in use, so that substantial advantages and benefits can be derived by the user of the device as well as by the user of the end mills, which are more accurately and concentrically sharpened, with their concentricity being properly and efiectively maintained.

My invention also comprises such other objects, advantages and capabilities as will later more fully appear and which are inherently possessed by my invention.

While I have shown in the accompanying drawings a preferred embodiment of my invention, it should be understood that the same is susceptible of modification and change without departing from the spirit of my invention.

Referring to the drawings, FIG. 1 is a side elevational View of my end mill sharpening device in use;

FIG. 2 is an enlarged sectional view of a portion of the same, taken along line 2-2 of FIG. 1;

FIG. 3 is a further enlarged sectional View of a portion of the same, taken along line 33 of FIG. 2, showing the relationship between the holding means, end mill and grinding wheel during the sharpening operation;

FIG. 4 is an even further enlarged sectional view taken along line 44 of FIG. 1, showing the bearing assembly which is identical for all of the rollers, as indicated in dotted lines in FIG. 2 of the drawings.

A preferred embodiment which has been selected to illustrate my invention comprises a supporting base 10, upon which is mounted a rotatable grinding wheel 11, which is driven by an electrically operated motor 12. Control means 13 are provided for adjusting the vertical height of the motor 12 and grinding wheel 11, such control means and mechanism being conventional and well known in the art.

Mounted adjacent to the lower portion of the grinding wheel 11 is a vertically directed guide 14, which is preferably formed of hardened steel or the like. In use, the upper free end of the guide 14 fits within the flute of the end :mill, in order to guide the rotation and/or movement of the end mill with respect to the grinding wheel 11. The lower end of the guide 14 is adjustably held by means of a set screw 15.

The end mill holding means 16 is mounted on the upper portion of the table 17, which is adjustable laterally with respect to the grinding wheel 11 to accommodate and adjust for different sizes of end mill diameters, the direction of adjustment being indicated by the arrows in FIG. 1 of the drawings. Control means 18 are provided to accomplish such adjustment, such control means and adjusting'mechanism being conventional and well known in the art.

The table 17 is also mounted for reciprocal movement longitudinally along a line parallel with the axis of the grinding wheel 11. Control means 19 are provided to control such movement, such control means and movement mechanism being conventional and well known in the art.

The holding means 16 includes a post 20 which extends vertically upwardly from the upper portion of the table 17, adjacent to the grinding wheel 11. Extending through the post 20 are a pair of elongated cylindrical spindles, the midportion of each spindle being rotatably journaled in a pair of bearings 23 mounted at the opposite ends of a sleeve 24 which is fixedly held within the post 20. The ends of the spindles 21 carry elongated cylindrical rollers 25, .26, 27 and 28, which are fixed with respect to the spindles 21 and which rotate with respect to the post 20.

Extending from the post 20 toward the grinding wheel 11 is a yoke which comprises a pair of horizontally directed arms 29. Referring to FIG. 4 of the drawings,

.the end mill.

another sleeve 30, which is mounted between the arms 29 is free to move horizontally between the arms 29, but is held against rotation.

.An elongated spindle 31 is rotatably journaled in a pair of bearings 32 carried by the opposite ends of the sleeve 30. Mounted on the opposite ends of the spindle 31 are apair of elongated cylindrical rollers 33 and 34. The axis of the spindle 31 is disposed along a horizontal line midway between the axes of the spindles 21.

An externally screw threaded rod 35 is fixedly mounted at one end thereof in the midportion of the sleeve 30. The rod 35 extends from the sleeve 30 through the post 20 between the sleeves 24 and protrudes outwardly from the side of the post 20 opposite from the yoke arms 29. A knob 36 is screw threadedly mounted on the free end of the rod 35 adjacent to the side of the post 20.

, In'use, the knob 36 is rotated on the rod 35 to release the roller 34 for horizontal movement away from the rollers 25 and-27. The roller 34 should be moved a sufflcient distance to permit the insertion of the shank of an end mill 37 between the circumferences of all three rollers 25, 27 and 34, with the fluted portion of the end mill 37 protruding from the ends of the rollers toward the grinding wheel 11.

At the same time, the shank of a sizing and guiding member 38 having the same diameter shank as the shank of the end mill being sharpened is inserted between the circumferences of the opposite set of'three rollers 33, 26 and 28, with a gripping portion of the sizing and guiding member .38 protruding from the ends of the rollers in a direction away from the grinding wheel 11.

The knob 36 is then rotated and tightened on the rod 35 to grip the end mill 37 and the sizing and guiding member 38 simutaneously. It will be noted that the end mill 37 is held so that its center or longitudinal axis is disposed an equal distance from the centers or longitudinal axes of all three of the rollers 25, 27 and 34..This relationship never changes or varies as the rollers and end mill are rotated, nor does it change with the size of It is possible for a single size of fixture to accommodate a'wide' range of sizes of end mills. For example, a device constructed in the manner shown in the drawings can hold 7 sizes ranging'from to 1 /2" and the fixture can be made larger or smaller, as desired.

In use, after the end mill 37 has been mounted between the rollers, the control 19 is operated to move the table 17, including the end mill holding means 16 and end mill 37, toward the grinding wheel 11. .The controls 13, 18 and 19 are adjusted,'if necessary, in order to orient the end mill 37 so that the guide 14 will engage one of the flutes of the end mill 37. The controls 13 and 18 are then left as set and only the control 19 is operated thereafter, in order to move the end mill past the grinding wheel 11.

7 The guide 14 is so oriented with respect to the grinding wheel 11 that when it travels along the flutes of the end mill 37, the cutting edge of the end mill engages the grinding wheel 11 and is sharpened. The sharpening operation is repeated as manytimes as is necessary or desirable to complete the'sharpening of the end mill.

- The operator customarily operates the control 19 with between the cutting surfaces of the end mill 37 and the,

grinding wheel .11. V

The device can also beused with end mills having straight rather than-helical flutes. Insharpening 'such end mills, the end is moved in a substantially straight line past the grinding wheel and is rotated only to the extent necessary to assure proper sharpening. V

It will be noted that the end mill is held so that its longitudinal axis is straight, as a result of the three point engagement between the rollers and the shank of the end mill. The longitudinal axis of the end mill remains unchanged during the entire sharpening operation and concentricity of the sured.

I claim:

1. In an end mill sharpening devicehaving grinding means, guide means for engaging the flutes of the end mill and a table mounted for reciprocal movement with respect to the grinding means and guide means, end mill holding means mounted on said table, said holding means comprises a vertically directed post, a pair of horizontal: I

lydirected elongated spindles. rotatably extending through said post, said spindles being disposed one above the other, a roller carried by each end of each of "said spindles,

arms, a roller carried by each end of said third spindle, a

rodsecured at one end thereof to said third spindle, said rod extending through said post, a knob rotatably mounted on said rod on the opposite side of said post from said third spindle, said knob adapted to be loosenedfor tightened to permit or prevent horizontal movement of said third spindle, the rollers on one end of said spindles I being adapted to hold the shank of an end mill between one hand and places his other hand on the .outwardly protruding gripping portion of the sizing and guiding member 38. As the guide 14 follows the helical flute of the end mill 37, it causes-the end mill 37 to rotate as it moves past the grinding wheel 11.-'RQt3tlOD. of the end mill 37 is permitted by the simultaneous, rotation of all three of the spindles and the rollers mounted thereon. The end mill 37 is accordingly rotated and moved longitudinally during the sharpening operation.

As stated above, the operator customarily places one hand on the gripping portion of the sizing and guiding member 38 during the grinding operation in order to assist and control the rotational movement of the end the circumferences thereof with the portion of said end 7 mill to. be sharpened disposed adjacent to said grinding wheel, the rollers on the other end of said spindles hold-. mg between the circumferences thereof the shank of a sizing and guiding member having a diameter correspond? mg'to that of said end mill, said sizing and guiding memher having a protruding gripping portion adapted to be manually rotated to control 'the rotation of said end mill during the sharpening of said end mill.

2. In 'an .end mill sharpening device having grinding means, guide means for engagingthe end mill and a table mounted for reciprocal movement'with respect to the grinding means and'guide means, end mill holding means mounted on said table, said holding means compnsmg a vertically directed post, a pair of horizontally directed'elongated spindles rotatably extending through said post, a roller carried 'by'each end of each of said spindles, a third elongated spindle rotatably mounted adjacent to said post, a roller carried by eachend ofsaid third spindle, said third spindle being movable with respect to said pair of spindles, the rollers on one end of said spindles being adapted to hold the shankof an end mill 7' between the circumferences thereof with the portion of i said end mill to be sharpened'disposed adjacent to said grinding means, the rollers on the other ,end of said spindles holding between the circumferences thereofthe shank of a sizing and guiding member having'a' diameter corresponding to that of said end mill, said sizing and guiding member having a protruding gripping portion adapted to be manually rotated to control the rotation of said and mill during the sharpening of said end mill.

3. In an end'mill sharpening device having grinding sharpening end mill is accordingly asmeans, end mill holding means recip y movable i respect to said grinding Whee S holding means cluding three horizontally directed elongated rotatable spindles, a roller carried by each end of each of said spindles, the rollers on one end of said spindles bein adapted to hold the shank of an end mill between the circumferences thereof with the portion of said end mill to be sharpened disposed adjacent to said grinding means, the rollers on the other end of said spindles holding between the circumferences thereof the shank of a sizing and guiding member having a diameter corresponding to that of said end mill, said sizing and guiding member having a protruding gripping portion adapted to be manually rotated to control the rotation of said end mill during the sharpening of said end mill.

4. In an end mill sharpening device having grinding means, end mill holding means mounted for reciprocal movement with respect to said grinding means along the longitudinal axis of the end mill, said holding means comprising three rotatable rollers, at least one of said rollers being movable with respect to the other rollers to permit the insertion of the shank of an end mill between the circumferences of said rollers, said rollers being adapted to hold said end mill so that said end mill is rotatable about its longitudinal axis and said longitudinal axis is unchanged during the rotation and reciprocal movement of said end mill with respect to said grinding means, to maintain the concentricity of said end mill during the sharpening thereof, said rollers being mounted on spindles, a second set of three rollers mounted on said spindles and a sizing and guiding member having a shank mounted between the circumferences of the said second set of rollers and held thereby, the shank of said sizing and guiding member corresponding in diameter to the shank of the end mill being sharpened, said sizing and guiding member being rotatable to control the rotation of said rollers and said end mill.

5. In an end mill sharpening device having grinding means, end mill holding means mounted for reciprocal movement with respect to said grinding means along the longitudinal axis of the end mill, said holding means comprising three rotatable rollers, at least one of said rollers being movable with respect to the other rollers to permit the insertion of the shank of an end mill between the circumferences of said rollers, said rollers being adapted to hold said end mill so that said end mill is rotatable about its longitudinal axis and said longitudinal axis is unchanged during the rotation and reciprocal movement of said end mill with respect to said grinding means, to maintain the concentricity of said end mill during the sharpening thereof, a second set of three rollers connected to said first named rollers, whereby rotation of said second rollers causes rotation of said first named rollers, and a sizing and guiding member having a shank mounted between the circumferences of said second set of rollers and held thereby, said shank of said sizing and guiding member corresponding in diameter to the shank of the end mill being sharpened, said sizing and guiding member being rotatable to control the rotation of said end mill.

6. In a tool sharpening device having grinding means, tool holding means mounted for reciprocal movement with respect to said grinding means along the longitudinal axis of the tool, said holding means comprising three rotatable rollers, at least one of said rollers being movable with respect to the other rollers to permit the insertion of the shank of a tool between the circumferences of said rollers, said rollers holding said tool so that said tool is rotatable about its longitudinal axis and said longitudinal axis is unchanged during the rotation and reciprocal movement of said tool with respect to said grinding means, to maintain the concentricity of said tool during the sharpening thereof, and a second set of three rollers connected to said first named rollers, whereby rotation of said second rollers causes rotation of said first named rollers, and a guiding member mounted between the circumferences of said second set of rollers and held thereby, said guiding member being rotatable to control the rotation of said tool.

7. In a work member holding device, holding means comprising three rotatable rollers, said rollers being adapted to hold a work member inserted between the circumferences of said rollers, said rollers holding said Work member so that said work member is rotatable about its longitudinal axis and said longitudinal axis is unchanged during the rotation of said work member, and a second set of three rollers connected to said first named rollers, whereby rotation of said second rollers causes rotation of said first named rollers, and a guiding member mounted between the circumferences of said second set of rollers and held thereby, said guiding member being rotatable to control the rotation of said work member.

References Cited UNITED STATES PATENTS 2,411,972 12/1946 Melin 5195 2,569,855 10/ 1951 Hertlein 5195 2,741,074 4/ 1956 Kopczynski 5l236 X 2,875,560 3/1959 Rocco 51-232 ROBERT C. RIORDON, Primary Examiner. D. G. KELLY, Assistant Examiner. 

1. IN AN END MILL SHARPENING DEVICE HAVING GRINDING MEANS, GUIDE MEANS FOR ENGAGING THE FLUTES OF THE END MILL AND A TABLE MOUNTED FOR RECIPROCAL MOVEMENT WITH RESPECT TO THE GRINDING MEANS AND GUIDE MEANS, END MILL HOLDING MEANS MOUNTED ON SAID TABLE, SAID HOLDING MEANS COMPRISES A VERTICALLY DIRECTED POST, A PAIR OF HORIZONTALLY DIRECTED ELONGATED SPINDLES ROTATABLY EXTENDING THROUGH SAID POST, SAID SPINDLES BEING DISPOSED ONE ABOVE THE OTHER, A ROLLER CARRIED BY EACH END OF EACH OF SAID SPINDLES, A YOKE INCLUDING A PAIR OF HORIZONTALLY DIRECTED ARMS EXTENDING FROM SAID POST TOWARD SAID GRINDING WHEEL, A THIRD ELONGATED SPINDLE ROTATABLY MOUNTED BETWEEN SAID ARMS, A ROLLER CARRIED BY EACH END OF SAID THIRD SPINDLE, A ROD SECURED AT ONE END THEREOF TO SAID THIRD SPINDLE, SAID ROD EXTENDING THROUGH SAID POST, A KNOB ROTATABLY MOUNTED ON SAID ROD ON THE OPPOSITE SIDE OF SAID POST FROM SAID THIRD SPINDLE, SAID KNOB ADAPTED TO BE LOOSENED OR TIGHTENED TO PERMIT OR PREVENT HORIZONTAL MOVEMENT OF SAID THIRD SPINDLE, THE ROLLERS ON ONE END OF SAID SPINDLES BEING ADAPTED TO HOLD THE SHANK OF AN END MILL BETWEEN THE CIRCUMFERENCES THEREOF WITH THE PORTION OF SAID END MILL TO BE SHARPENED DISPOSED ADJACENT TO SAID GRINDING WHEEL, THE ROLLERS ON THE OTHER END OF SAID SPINDLES HOLDING BETWEEN THE CIRCUMFERENCES THEREOF THE SHANK OF A SIZING AND GUIDING MEMBER HAVING A DIAMETER CORRESPONDING TO THAT OF SAID END MILL, SAID SIZING AND GUIDING MEMBER HAVING A PROTRUDING GRIPPING PORTION ADAPTED TO BE MANUALLY ROTATED TO CONTROL THE ROTATION OF SAID END MILL DURING THE SHARPENING OF SAID END MILL. 